This invention relates to two-way radios in general, and in particular to radios having a voice storage means, which can be utilized to store and later transmit a voice message. Known voice storage radios are utilized for voice mailbox purposes. That is, voice messages are either received and stored by the radio for later review, or the message is stored and later transmitted on command or request. These approaches provide for either incoming or outgoing voice mail.
When radios are operated on shared frequencies, it is important that only a single radio transmit on any give frequency, within a geographical area at a time. Where a radio is operating in a carrier squelch mode, the user can readily ascertain if the channel is in use by whether the radio is unsquelched, in which case the radio is producing an audio output. For coded squelch operation, such as subaudible tone or digital code, a monitor switch is often provided to permit the radio user to defeat the coded squelch operation to monitor the channel for activity. Some systems provide automatic transmit inhibit, preventing transmission by the radio if a signal is present on the channel.
Where a radio user desires to transmit a message on a busy channel, he must wait until the channel is clear prior to articulating the message. This is often a disruption to the user who wishes to proceed with other activities, but instead must remain ready to actuate the radio and talk when the channel becomes available. It is desirable to provide a means permitting the user to articulate his message inspite of a busy condition on the channel.